The Real King Al The Real King Aloha Hawaii. Diamond Dozen Diamond Dozen. Carry on Camping Carry on Camping. However, this is not mandatory and can be changed from game to game.

In some games, wild symbols can appear only on certain reels. Or, they can appear only during the bonus rounds. The player must refer to the rules and paytable of the game to learn about the landing rules.

Mobile is when the slot machine is hosted for online gambling and it is usually available for use on a phone, tablet, or other portable device.

These are often standalone mobile casino applications but are also found as part of the online casino site.

By , HTML5 technology and the advancement of mobile browsers had negated the need for standalone mobile apps. New slots are, by majority, playable on both mobile and desktop devices.

Each machine has a table that lists the number of credits the player will receive if the symbols listed on the pay table line up on the pay line of the machine.

Some symbols are wild and can represent many, or all, of the other symbols to complete a winning line. Especially on older machines, the pay table is listed on the face of the machine, usually above and below the area containing the wheels.

Most video machines display the pay table when the player presses a "pay table" button or touches "pay table" on the screen; some have the pay table listed on the cabinet as well.

Historically, all slot machines used revolving mechanical reels to display and determine results. Although the original slot machine used five reels, simpler, and therefore more reliable, three reel machines quickly became the standard.

Although the number of symbols eventually increased to about 22, allowing 10, combinations, [21] this still limited jackpot sizes as well as the number of possible outcomes.

In the s, however, slot machine manufacturers incorporated electronics into their products and programmed them to weight particular symbols.

Thus the odds of losing symbols appearing on the payline became disproportionate to their actual frequency on the physical reel.

A symbol would only appear once on the reel displayed to the player, but could, in fact, occupy several stops on the multiple reel.

With microprocessors now ubiquitous, the computers inside modern slot machines allow manufacturers to assign a different probability to every symbol on every reel.

In the s in the UK machines embodying microprocessors became common. These used a number of features to ensure the payout was controlled within the limits of the gambling legislation.

As the coin was inserted into the machine it could go one of two routes, either direct into the cashbox for the benefit of the owner, or alternatively it would go into a channel that formed the payout reservoir, the microprocessor monitoring the number of coins in this channel.

The drums themselves were driven by stepper motors, controlled by the processor and with proximity sensors monitoring the position of the drums.

A "look up table" within the software allows the processor to know what symbols were being displayed on the drums to the gambler.

This allowed the system to control the level of payout by stopping the drums at positions it had determined. If the payout channel had filled up, the payout became more generous, if nearly empty, less so thus giving good control of the odds.

The video slot machine is a more recent innovation, with no moving parts at all — instead a graphical representation of one appears on screen.

In addition, because there are no mechanical constraints on the design of video slot machines, most display five reels rather than three.

This greatly expands the number of possibilities: As there are so many combinations given by five reels, the manufacturers do not need to weight the payout symbols although some may still do so.

Instead, higher paying symbols will typically appear only once or twice on each reel, while more common symbols, earning a more frequent payout, will appear many times.

Video slot machines typically encourage the player to play multiple "lines", so rather than simply taking the middle of the three symbols displayed on each reel, a line could go from top left to bottom right, or any of the other patterns specified by the manufacturer.

As each symbol is equally likely, there is no difficulty for the manufacturer in allowing the player to take any or all of the possible lines on offer — the long-term return to player will be the same.

The difference for the player is that the more lines he plays the more likely he is to get paid on a given spin — though of course he is betting more in the first place.

The player is encouraged to keep playing to reach the bonus: All modern machines are designed using pseudo random number generators "PRNGs" , which are constantly generating a sequence of simulated random numbers, at a rate of hundreds or perhaps thousands per second.

As soon as the "Play" button is pressed, the most recent random number is used to determine the result. This means that the result varies depending on exactly when the game is played.

A fraction of a second earlier or later, and the result would be different. Having access to the PRNG code and seed values, Ronald Dale Harris , a former slot machine programmer, discovered equations for specific gambling games like Keno that allowed him to predict what the next set of selected numbers would be based on the previous games played.

Most machines are designed to defeat this by generating numbers even when the machine is not being played, so the player cannot tell where in the sequence they are, even if they know how the machine was programmed.

This is known as the "theoretical payout percentage" or RTP, "return to player". The minimum theoretical payout percentage varies among jurisdictions and is typically established by law or regulation.

The winning patterns on slot machines — the amounts they pay and the frequencies of those payouts — are carefully selected to yield a certain fraction of the money played to the "house" the operator of the slot machine , while returning the rest to the players during play.

Within some EGM development organizations this concept is referred to simply as "par. Changing the payout percentage after a slot machine has been placed on the gaming floor requires a physical swap of the software or firmware , which is usually stored on an EPROM but may be loaded onto non-volatile random access memory NVRAM or even stored on CD-ROM or DVD , depending on the capabilities of the machine and the applicable regulations.

Based on current technology, this is a time-consuming process and as such is done infrequently. Other jurisdictions, including Nevada, randomly audit slot machines to ensure that they contain only approved software.

Historically, many casinos, both online and offline, have been unwilling to publish individual game RTP figures, making it impossible for the player to know whether they are playing a "loose" or a "tight" game.

Since the turn of the century some information regarding these figures has started to come into the public domain either through various casinos releasing them—primarily this applies to online casinos—or through studies by independent gambling authorities.

The return to player is not the only statistic that is of interest. The probabilities of every payout on the pay table is also critical.

For example, consider a hypothetical slot machine with a dozen different values on the pay table. However, the probabilities of getting all the payouts are zero except the largest one.

Also, most people would not win anything, and having entries on the paytable that have a return of zero would be deceptive. As these individual probabilities are closely guarded secrets, it is possible that the advertised machines with high return to player simply increase the probabilities of these jackpots.

The added advantage is that these large jackpots increase the excitement of the other players. This game, in its original form, is obsolete, so these specific probabilities do not apply.

He only published the odds after a fan of his sent him some information provided on a slot machine that was posted on a machine in the Netherlands.

The psychology of the machine design is quickly revealed. There are 13 possible payouts ranging from 1: Most players assume the likelihood increases proportionate to the payout.

The one midsize payout that is designed to give the player a thrill is the It is programmed to occur an average of once every plays.

In contrast the The highest payout of 2, The player who continues to feed the machine is likely to have several midsize payouts, but unlikely to have a large payout.

He quits after he is bored or has exhausted his bankroll. Despite the fact that they are confidential, occasionally a PAR sheet is posted on a website.

They have limited value to the player, because usually a machine will have 8 to 12 different possible programs with varying payouts.

In addition, slight variations of each machine e. The casino operator can choose which EPROM chip to install in any particular machine to select the payout desired.

The result is that there is not really such a thing as a high payback type of machine, since every machine potentially has multiple settings.

Without revealing the proprietary information, he developed a program that would allow him to determine with usually less than a dozen plays on each machine which EPROM chip was installed.

Then he did a survey of over machines in 70 different casinos in Las Vegas. He averaged the data, and assigned an average payback percentage to the machines in each casino.

The resultant list was widely publicized for marketing purposes especially by the Palms casino which had the top ranking.

One reason that the slot machine is so profitable to a casino is that the player must play the high house edge and high payout wagers along with the low house edge and low payout wagers.

Other bets have a higher house edge, but the player is rewarded with a bigger win up to thirty times in craps.

The player can choose what kind of wager he wants to make. A slot machine does not afford such an opportunity. Theoretically, the operator could make these probabilities available, or allow the player to choose which one so that the player is free to make a choice.

However, no operator has ever enacted this strategy. Different machines have different maximum payouts, but without knowing the odds of getting the jackpot, there is no rational way to differentiate.

In many markets where central monitoring and control systems are used to link machines for auditing and security purposes, usually in wide area networks of multiple venues and thousands of machines, player return must usually be changed from a central computer rather than at each machine.

A range of percentages is set in the game software and selected remotely. The change cannot be done instantaneously, but only after the selected machine has been idle for at least four minutes.

After the change is made, the machine must be locked to new players for four minutes and display an on-screen message informing potential players that a change is being made.

Often machines are linked together in a way that allows a group of machines to offer a particularly large prize, or "jackpot". Each slot machine in the group contributes a small amount to this progressive jackpot , awarded to a player who gets, for example, a royal flush on a video poker machine or a specific combination of symbols on a regular or nine-line slot machine.

The amount paid for the progressive jackpot is usually far higher than any single slot machine could pay on its own. In some cases multiple machines are linked across multiple casinos.

In these cases, the machines may be owned by the manufacturer, who is responsible for paying the jackpot.

The casinos lease the machines rather than owning them outright. Casinos in New Jersey, Nevada, and South Dakota now offer multi-state progressive jackpots, which now offer bigger jackpot pools.

Mechanical slot machines and their coin acceptors were sometimes susceptible to cheating devices and other scams.

One historical example involved spinning a coin with a short length of plastic wire. The weight and size of the coin would be accepted by the machine and credits would be granted.

However, the spin created by the plastic wire would cause the coin to exit through the reject chute into the payout tray.

This particular scam has become obsolete due to improvements in newer slot machines. Another obsolete method of defeating slot machines was to use a light source to confuse the optical sensor used to count coins during payout.

Modern slot machines are controlled by EPROM computer chips and, in large casinos, coin acceptors have become obsolete in favor of bill acceptors.

These machines and their bill acceptors are designed with advanced anti-cheating and anti-counterfeiting measures and are difficult to defraud.

Early computerized slot machines were sometimes defrauded through the use of cheating devices, such as the "slider" or "monkey paw".

Malfunctioning electronic slot machines are capable of indicating jackpot winnings far in excess of those advertised. In the United States, the public and private availability of slot machines is highly regulated by state governments.

Many states have established gaming control boards to regulate the possession and use of slot machines. Nevada is the only state that has no significant restrictions against slot machines both for public and private use.

In New Jersey , slot machines are only allowed in hotel casinos operated in Atlantic City. Several states Illinois , Indiana , Louisiana and Missouri allow slot machines as well as any casino-style gambling only on licensed riverboats or permanently anchored barges.

Since Hurricane Katrina , Mississippi has removed the requirement that casinos on the Gulf Coast operate on barges and now allows them on land along the shoreline.

Delaware allows slot machines at three horse tracks; they are regulated by the state lottery commission. In Wisconsin, bars and taverns are allowed to have up to five machines.

These machines usually allow a player to either take a payout, or gamble it on a double-or-nothing "side game". A player redeems his winnings by pressing a button to print a ticket, which the bartender redeems for cash.

The territory of Puerto Rico places significant restrictions on slot machine ownership, but the law is widely flouted and slot machines are common in bars and coffeeshops.

The remaining states allow slot machines of a certain age typically 25—30 years or slot machines manufactured before a specific date. For a detailed list of state-by-state regulations on private slot machine ownership, see U.

Native American casinos located in reservations are not permitted to have slot machines unless the tribe first reaches a pact with the state in which it is located per Indian Gaming Regulatory Act.

Typically, a pact entitles the state to receive a fraction of the gross revenue from slot machines. Some states have restrictions on the type called "class" of slot machines that can be used in a casino or other gaming area.

The Indian Gaming Regulatory Act establishes three classes of games with a different regulatory scheme for each: Class I gaming is defined as 1 traditional Indian gaming, which may be part of tribal ceremonies and celebrations, and 2 social gaming for minimal prizes.

Class II gaming is defined as the game of chance commonly known as bingo whether or not electronic, computer, or other technological aids are used in connection therewith and, if played in the same location as the bingo , pull tabs, punch board, tip jars, instant bingo, and other games similar to bingo.

Class II gaming also includes non-banked card games , that is, games that are played exclusively against other players rather than against the house or a player acting as a bank.

The Act specifically excludes slot machines or electronic facsimiles of any game of chance from the definition of class II games. Tribes retain their authority to conduct, license, and regulate class II gaming, provided it complies with the Act - including the requirement that the Tribal government adopt a gaming ordinance approved by the National Indian Gaming Commission NIGC.

Tribal governments are the primary entity responsible for regulating class II gaming on its lands. Only Hawaii and Utah continue to prohibit all types of gaming.

The definition of class III gaming is broad. It includes all forms of gaming that are neither class I nor II. Games commonly played at casinos , such as slot machines , blackjack , craps , and roulette , clearly fall in the class III category, as well as wagering games and electronic facsimiles of any game of chance.

Generally, class III is often referred to as casino-style gaming. The regulatory scheme for class III gaming is more complex than a casual reading of the statute might suggest.

Although Congress clearly intended regulatory issues to be addressed in Tribal-State compacts , it left a number of key functions in federal hands, including approval authority over compacts, management contracts, and Tribal gaming ordinances.

Congress also vested the Commission with broad authority to issue regulations in furtherance of the purposes of the Act. Many American casinos offer free memberships in "slot clubs", which return a fraction of the amount of money that is bet in the form of comps complimentary food, drinks, hotel rooms, or merchandise , or sometimes as cash or a promise to pay cash at a later date.

The slot machine with 3 reels is a classical variant that is often used in the ground gaming establishments. Currently, these gaming devices are gradually sliding and here come contemporary models instead of them.

They are very alluring for keen players because of their numerical coefficients, free spins, and jackpots, which is regarded as accumulative.

The slot machine with 7 reels is accessible only in the exclusive online surroundings but they continue to gain an obvious favorite in the circle of players as well.

They vary from others as they do not have bonus rounds and there is also a minimum number of lines up to 10 but they allow gamers to attain minor payments several times in a row.

The slot machine with 9 reels is not very common but still, it attracts gamblers with its creative design and captivating bonus regimes. The lines are set up in a vertical, horizontal and diagonal way.

They are very popular due to rapid and progressive jackpots. These fall under the jurisdiction of the province or territory without reference to the federal government.

Thus no two provincial regulatory or operational regimes are the same. The 10 provinces all have gaming departments and slot machine play is available in venues across all.

Part of the revenues go to the local government which in turn gives a percentage to the federal government. Choice of slots available is a province by province negotiation with the local Gaming Department.

Individual territories have such small populations that there are no dedicated departments or land based facilities to play. Only 12 First Nation casinos exist scattered over five provinces.

The Assembly of First Nations view jurisdiction over gaming on First Nation land as part of their constitutional rights protected by section 35 1 of the Constitution Act, All provinces have dedicated problem gambling help lines and research, and the territories have health and social service support for individuals with gambling problems.

These machines have additional bonusing and second-screen features such as free games and bonus levels.

They also allow for multiple lines up to or multiple ways up to 3, to be played. Late in , there were , poker machines operating in Australia, which was 2.

On multiway games, players play the entire position of each reel instead of fixed lines or patterns. For instance, if a player plays 1 reel on a way game, they receive three symbols in the first reel which pay anywhere in the three positions, while all other reels pay in the centre only, with unused areas darkened.

On the other end of the scale, if the player plays 5 reels, symbols can appear anywhere in the window and will pay as long as there is one in each reel.

Most games however still require the symbols appearing left to right, sometimes this even includes scatters. Other multiway games give you even more ways by using a 4x5 or 5x5 pattern, where there are up to 5 symbols in each reel, allowing for up to 1, and 3, ways to win respectively.

These games typically cost more than their way Reel Power counterparts. Recently, IGT has also started to manufacture multiway games.

Gaming machine manufacturer Konami Australia also made an alternative way of gaming by using patterns, where symbols pay adjacent to one another.

Most of these games have a hexagonal reel formation, and much like multiway games, any patterns not played are darkened out of use.

On both systems, scatter symbols still pay in the darkened areas just like standard machines where scatters do not have to appear on a payline.

The laws regulating the use of gaming machines in Australia are a matter for State governments, and as such they vary between States. Gaming machines are found in casinos approximately one in each major city as well as pubs and clubs in some states usually sports, social, or RSL clubs.

The first Australian state to legalize this style of gambling was New South Wales in when they were made legal in all registered clubs in the state.

There are suggestions that the proliferation of poker machines has led to increased levels of problem gambling ; however, the precise nature of this link is still open to research.

The primary reason for this is that gaming machines have been legal in the state of New South Wales since and over that time the number of machines has grown to 97, at December , including the Australian Capital Territory.

By way of comparison, the US State of Nevada which legalised gaming including slots several decades before NSW, had , slots operating.

This new law also banned machines which would automatically play with the button held. These combinations are stated to be played on a minimum bet usually 1 credit per line, with 1 line or reel played , excluding feature wins.

Western Australia only permits the use of particular forms of gaming machine in Burswood casino , and no gaming machines may be used elsewhere.

This policy the most restrictive in Australia had a long historical basis, and was reaffirmed by the Royal Commission into Gambling:.

It requires no thought, no skill or social contact. The odds are never about winning. Watching people playing the machines over long periods of time, the impressionistic evidence at least is that they are addictive to many people.

Historically poker machines have been banned from Western Australia and we consider that, in the public interest, they should stay banned. Independent candidate Andrew Wilkie , an anti-pokies campaigner, was elected to the Australian House of Representatives seat of Denison at the federal election.

Wilkie was one of four crossbenchers who supported the Gillard Labor government following the hung parliament result. Wilkie immediately began forging ties with Xenophon as soon as it was apparent that he was elected.

In Russia, slot clubs appeared quite late, only in Before slot machines were only in the casino and in small shops, but later slot clubs began to grow over the country.

The most popular and numerous clubs were "Vulcan " and "Taj Mahal". After , when a ban on gambling establishments, almost all slot clubs disappeared, and appeared only in a specially authorized gambling zones.

The provision of slot machines is covered by the Gambling Act This superseded the Gaming Act Slot machines in the UK are categorised by definitions produced by the Gambling Commission as part of the legislation brought in with the Gambling Act of Casinos built under the provisions of the Act are allowed to house up to twenty machines categories B to D or any number of C or D machines instead.

As defined by the Act, large casinos will have a maximum of one hundred and fifty machines of any combination of machines in categories B to D, within the total limit of one hundred and fifty subject to machine to table ratio of 5: Category A games were defined in preparation for the planned " Super Casinos.

As a result, there are no lawful Category A games in the UK. Category B games are divided into subcategories. However, the differences between B1, B3 and B4 games are mainly the stake and prizes as defined in the above table.

FOBTs are mainly found in licensed betting shops , or bookmakers, usually in the form of electronic roulette. The games are based on a random number generator and thus the probability of getting the jackpot in each game is independent of any other game, and these probabilities are all equal.

Rumble Rumble Rumble Rumble. The Dragon The Dragon. Retrieved 2 October Horror Castle Horror Castle. Moon Warriors Moon Warriors. Retrieved 7 February Ancient Secrets Ancient Secrets. Skill stop buttons predated the Bally electromechanical slot machines of the s and 70s. Lucky Links Lucky Links. Caribic casino bonus code Long Bao Shi. Family Fortunes Family Fortunes. The Enchantment The Enchantment. Invaders from the Planet Live eurojackpot. Strip to Win Strip to Win. Tree of Fortune Tree of Fortune. Jackpot Jewels Jackpot Jewels. African Dream African Dream. Aloha Party Aloha Party. Lion Explorer Lion Explorer. Casino slowenien grenze to Riches Ra to Riches. Per handyrechnung zahlen of the Nil Holmes and the Stolen Stones. The Mummy The Mummy. The symbols are usually brightly colored and easily recognizable, big game casino as images of fruits, polen gegen schottland live stream or letters, and simple shapes such as bells, diamonds, or hearts; newer video slot machines use animated cartoon characters and images of popular actors or singers in the case of themed slot machines, as described below. Red Hot Chili Ch Golden Monkey Golden Monkey. While the machine is in bonus mode, the player is entertained with special winning scenes on the LCD display, and energizing music is heard, payout after secrets of atlantis netent. Super Times Pay Hot Roll.

Game of Kings Game of Kings. Kingdom of Cash Kingdom of Cash. The Price is Rig On the Wheel of Fortune video machine, the chances of triggering the bonus round or winning the maximum jackpot are exactly the same regardless of the number of coins bet on each line.

Large denomination slot machines are usually cordoned off from the rest of the casino into a "High Limit" area, often with a separate team of attendants to cater to the needs of those who play there.

In the last few years, new multi-denomination slot machines have been introduced. With these slot machines, the player can choose the value of each credit wagered the stake from a list of options.

Bonus is a special feature of the particular game theme, which is activated when certain symbols appear in a winning combination.

Bonuses vary depending upon the game. In other bonus rounds, the player is presented with several items on a screen from which to choose.

As the player chooses items, a number of credits is revealed and awarded. Some bonuses use a mechanical device, such as a spinning wheel, that works in conjunction with the bonus to display the amount won.

Some machines feature two or more of these bonus styles as part of the same game. Candle is a light on top of the slot machine. It flashes to alert the operator that change is needed, hand pay is requested or a potential problem with the machine.

It can be lit by the player by pressing the "service" or "help" button. Coin hopper is a container where the coins that are immediately available for payouts are held.

When a certain preset coin capacity is reached, a coin diverter automatically redirects, or "drops," excess coins into a "drop bucket" or "drop box.

Credit meter is a visual LED display of the amount of money or number of credits on the machine. On video reel machines this is either a simulated LED display, or represented in a different font altogether, based on the design of the game graphics.

Typically, a drop bucket is used for low denomination slot machines and a drop box is used for high denomination slot machines.

A drop box contains a hinged lid with one or more locks whereas a drop bucket does not contain a lid. The contents of drop buckets and drop boxes are collected and counted by the casino on a scheduled basis.

Free Spin is a term used in slot games and online slot games to specify that the spin will be completed without a charge or on the same wager.

Free spins can get triggered by a number of things, each game uses a different method. Usually, landing a number of special symbols on reels is required to activate the free spins bonus round.

Mostly scatter symbols are preferred for this activation, although wild symbols or a completely different symbol dedicated for this feature can be used too.

In most slot games, landing at least three special symbols on reels is mandatory to trigger the feature. Once triggered, free spins bonus round award a number of spins free of charge to the player.

The number of free spins differ from game to game. If there is the ability to re-trigger free spins during the free spin bonus there is no theoretical limit to the number of free spins obtainable.

The spins are automatically used by the game and the player keeps any profit after the spins are complete. A single free spin is sometimes called a respin.

Hand pay refers to a payout made by an attendant or at an exchange point "cage" , rather than by the slot machine itself.

Usually, the maximum amount is set at the level where the operator must begin to deduct taxes. A hand pay could also be necessary as a result of a short pay.

Hopper fill slip is a document used to record the replenishment of the coin in the coin hopper after it becomes depleted as a result of making payouts to players.

The slip indicates the amount of coin placed into the hoppers, as well as the signatures of the employees involved in the transaction, the slot machine number and the location and the date.

Low Level or Slant Top slot machines include a stool so the player has sitdown access. Stand Up or Upright slot machines are played while standing.

Optimal play is a payback percentage based on a gambler using the optimal strategy in a skill-based slot machine game.

Payline is a line that crosses through one symbol on each reel, along which a winning combination is evaluated. Classic spinning reel machines usually have up to nine paylines, while video slot machines may have as many as one hundred.

Paylines could be of various shapes horizontal, vertical, oblique, triangular, zigzag, etc. Rollup is the process of dramatizing a win by playing sounds while the meters count up to the amount that has been won.

Short pay refers to a partial payout made by a slot machine, which is less than the amount due to the player. This occurs if the coin hopper has been depleted as a result of making earlier payouts to players.

The remaining amount due to the player is either paid as a hand pay or an attendant will come and refill the machine.

Scatter Symbol It is required to place at least two of the same symbols on a pay line to get paid in slot games. However, scatter symbols work differently and award a prize whether they are placed on a pay line or not.

But the player still needs to get at least two of them in modern slot games. The more, the better. Scatter symbols are usually used to award a number of free spins.

The number of free spins differs from game to game; i. They can also award coin prizes, based on their number. The prizes are usually small, but they are paid in addition to other winnings.

The scatter symbol is usually a special symbol, which means the wild symbol cannot replace it, although in some games the wild symbol also substitutes for scatters.

Slot variance is a measure of risk associated with playing a slot machine. A low variance slot machine has regular but smaller wins and a high variance slot machine has fewer but bigger wins.

Taste is a reference to the small amount often paid out to keep a player seated and continuously betting. Only rarely will machines fail to pay out even the minimum placed a bet over the course of several pulls.

Tilt Electromechanical slot machines usually include an electromechanical " tilt switch ", which makes or breaks a circuit if the machine is tilted or otherwise tampered with, and so triggers an alarm.

While modern machines no longer have tilt switches, any kind of technical fault door switch in the wrong state, reel motor failure, out of paper, etc.

Theoretical Hold Worksheet A document provided by the manufacturer for all slot machines, which indicates the theoretical percentage that the slot machine should hold based on the amount paid in.

The worksheet also indicates the reel strip settings, number of coins that may be played, the payout schedule, the number of reels and other information descriptive of the particular type of slot machine.

Wild Symbol Wild symbols act like joker cards in a slot game. Basically, they substitute for all other symbols in the game, usually except for other special symbols, such as scatter and jackpot.

They can appear on any of the reels. However, this is not mandatory and can be changed from game to game. In some games, wild symbols can appear only on certain reels.

Or, they can appear only during the bonus rounds. The player must refer to the rules and paytable of the game to learn about the landing rules.

Mobile is when the slot machine is hosted for online gambling and it is usually available for use on a phone, tablet, or other portable device.

These are often standalone mobile casino applications but are also found as part of the online casino site. By , HTML5 technology and the advancement of mobile browsers had negated the need for standalone mobile apps.

New slots are, by majority, playable on both mobile and desktop devices. Each machine has a table that lists the number of credits the player will receive if the symbols listed on the pay table line up on the pay line of the machine.

Some symbols are wild and can represent many, or all, of the other symbols to complete a winning line. Especially on older machines, the pay table is listed on the face of the machine, usually above and below the area containing the wheels.

Most video machines display the pay table when the player presses a "pay table" button or touches "pay table" on the screen; some have the pay table listed on the cabinet as well.

Historically, all slot machines used revolving mechanical reels to display and determine results. Although the original slot machine used five reels, simpler, and therefore more reliable, three reel machines quickly became the standard.

Although the number of symbols eventually increased to about 22, allowing 10, combinations, [21] this still limited jackpot sizes as well as the number of possible outcomes.

In the s, however, slot machine manufacturers incorporated electronics into their products and programmed them to weight particular symbols.

Thus the odds of losing symbols appearing on the payline became disproportionate to their actual frequency on the physical reel.

A symbol would only appear once on the reel displayed to the player, but could, in fact, occupy several stops on the multiple reel.

With microprocessors now ubiquitous, the computers inside modern slot machines allow manufacturers to assign a different probability to every symbol on every reel.

In the s in the UK machines embodying microprocessors became common. These used a number of features to ensure the payout was controlled within the limits of the gambling legislation.

As the coin was inserted into the machine it could go one of two routes, either direct into the cashbox for the benefit of the owner, or alternatively it would go into a channel that formed the payout reservoir, the microprocessor monitoring the number of coins in this channel.

The drums themselves were driven by stepper motors, controlled by the processor and with proximity sensors monitoring the position of the drums.

A "look up table" within the software allows the processor to know what symbols were being displayed on the drums to the gambler. This allowed the system to control the level of payout by stopping the drums at positions it had determined.

If the payout channel had filled up, the payout became more generous, if nearly empty, less so thus giving good control of the odds.

The video slot machine is a more recent innovation, with no moving parts at all — instead a graphical representation of one appears on screen.

In addition, because there are no mechanical constraints on the design of video slot machines, most display five reels rather than three.

This greatly expands the number of possibilities: As there are so many combinations given by five reels, the manufacturers do not need to weight the payout symbols although some may still do so.

Instead, higher paying symbols will typically appear only once or twice on each reel, while more common symbols, earning a more frequent payout, will appear many times.

Video slot machines typically encourage the player to play multiple "lines", so rather than simply taking the middle of the three symbols displayed on each reel, a line could go from top left to bottom right, or any of the other patterns specified by the manufacturer.

As each symbol is equally likely, there is no difficulty for the manufacturer in allowing the player to take any or all of the possible lines on offer — the long-term return to player will be the same.

The difference for the player is that the more lines he plays the more likely he is to get paid on a given spin — though of course he is betting more in the first place.

The player is encouraged to keep playing to reach the bonus: All modern machines are designed using pseudo random number generators "PRNGs" , which are constantly generating a sequence of simulated random numbers, at a rate of hundreds or perhaps thousands per second.

As soon as the "Play" button is pressed, the most recent random number is used to determine the result. This means that the result varies depending on exactly when the game is played.

A fraction of a second earlier or later, and the result would be different. Having access to the PRNG code and seed values, Ronald Dale Harris , a former slot machine programmer, discovered equations for specific gambling games like Keno that allowed him to predict what the next set of selected numbers would be based on the previous games played.

Most machines are designed to defeat this by generating numbers even when the machine is not being played, so the player cannot tell where in the sequence they are, even if they know how the machine was programmed.

This is known as the "theoretical payout percentage" or RTP, "return to player". The minimum theoretical payout percentage varies among jurisdictions and is typically established by law or regulation.

The winning patterns on slot machines — the amounts they pay and the frequencies of those payouts — are carefully selected to yield a certain fraction of the money played to the "house" the operator of the slot machine , while returning the rest to the players during play.

Within some EGM development organizations this concept is referred to simply as "par. Changing the payout percentage after a slot machine has been placed on the gaming floor requires a physical swap of the software or firmware , which is usually stored on an EPROM but may be loaded onto non-volatile random access memory NVRAM or even stored on CD-ROM or DVD , depending on the capabilities of the machine and the applicable regulations.

Based on current technology, this is a time-consuming process and as such is done infrequently. Other jurisdictions, including Nevada, randomly audit slot machines to ensure that they contain only approved software.

Historically, many casinos, both online and offline, have been unwilling to publish individual game RTP figures, making it impossible for the player to know whether they are playing a "loose" or a "tight" game.

Since the turn of the century some information regarding these figures has started to come into the public domain either through various casinos releasing them—primarily this applies to online casinos—or through studies by independent gambling authorities.

The return to player is not the only statistic that is of interest. The probabilities of every payout on the pay table is also critical.

For example, consider a hypothetical slot machine with a dozen different values on the pay table. However, the probabilities of getting all the payouts are zero except the largest one.

Also, most people would not win anything, and having entries on the paytable that have a return of zero would be deceptive.

As these individual probabilities are closely guarded secrets, it is possible that the advertised machines with high return to player simply increase the probabilities of these jackpots.

The added advantage is that these large jackpots increase the excitement of the other players. This game, in its original form, is obsolete, so these specific probabilities do not apply.

He only published the odds after a fan of his sent him some information provided on a slot machine that was posted on a machine in the Netherlands.

The psychology of the machine design is quickly revealed. There are 13 possible payouts ranging from 1: Most players assume the likelihood increases proportionate to the payout.

The one midsize payout that is designed to give the player a thrill is the It is programmed to occur an average of once every plays.

In contrast the The highest payout of 2, The player who continues to feed the machine is likely to have several midsize payouts, but unlikely to have a large payout.

He quits after he is bored or has exhausted his bankroll. Despite the fact that they are confidential, occasionally a PAR sheet is posted on a website.

They have limited value to the player, because usually a machine will have 8 to 12 different possible programs with varying payouts.

In addition, slight variations of each machine e. The casino operator can choose which EPROM chip to install in any particular machine to select the payout desired.

The result is that there is not really such a thing as a high payback type of machine, since every machine potentially has multiple settings.

Without revealing the proprietary information, he developed a program that would allow him to determine with usually less than a dozen plays on each machine which EPROM chip was installed.

Then he did a survey of over machines in 70 different casinos in Las Vegas. He averaged the data, and assigned an average payback percentage to the machines in each casino.

The resultant list was widely publicized for marketing purposes especially by the Palms casino which had the top ranking.

One reason that the slot machine is so profitable to a casino is that the player must play the high house edge and high payout wagers along with the low house edge and low payout wagers.

Other bets have a higher house edge, but the player is rewarded with a bigger win up to thirty times in craps. The player can choose what kind of wager he wants to make.

A slot machine does not afford such an opportunity. Theoretically, the operator could make these probabilities available, or allow the player to choose which one so that the player is free to make a choice.

However, no operator has ever enacted this strategy. Different machines have different maximum payouts, but without knowing the odds of getting the jackpot, there is no rational way to differentiate.

In many markets where central monitoring and control systems are used to link machines for auditing and security purposes, usually in wide area networks of multiple venues and thousands of machines, player return must usually be changed from a central computer rather than at each machine.

A range of percentages is set in the game software and selected remotely. The change cannot be done instantaneously, but only after the selected machine has been idle for at least four minutes.

After the change is made, the machine must be locked to new players for four minutes and display an on-screen message informing potential players that a change is being made.

Often machines are linked together in a way that allows a group of machines to offer a particularly large prize, or "jackpot".

Each slot machine in the group contributes a small amount to this progressive jackpot , awarded to a player who gets, for example, a royal flush on a video poker machine or a specific combination of symbols on a regular or nine-line slot machine.

The amount paid for the progressive jackpot is usually far higher than any single slot machine could pay on its own.

In some cases multiple machines are linked across multiple casinos. In these cases, the machines may be owned by the manufacturer, who is responsible for paying the jackpot.

The casinos lease the machines rather than owning them outright. Casinos in New Jersey, Nevada, and South Dakota now offer multi-state progressive jackpots, which now offer bigger jackpot pools.

Mechanical slot machines and their coin acceptors were sometimes susceptible to cheating devices and other scams.

One historical example involved spinning a coin with a short length of plastic wire. The weight and size of the coin would be accepted by the machine and credits would be granted.

However, the spin created by the plastic wire would cause the coin to exit through the reject chute into the payout tray. This particular scam has become obsolete due to improvements in newer slot machines.

Another obsolete method of defeating slot machines was to use a light source to confuse the optical sensor used to count coins during payout.

Modern slot machines are controlled by EPROM computer chips and, in large casinos, coin acceptors have become obsolete in favor of bill acceptors.

These machines and their bill acceptors are designed with advanced anti-cheating and anti-counterfeiting measures and are difficult to defraud. Early computerized slot machines were sometimes defrauded through the use of cheating devices, such as the "slider" or "monkey paw".

Computerized slot machines are fully deterministic and thus outcomes can be sometimes successfully predicted. Malfunctioning electronic slot machines are capable of indicating jackpot winnings far in excess of those advertised.

In the United States, the public and private availability of slot machines is highly regulated by state governments. Many states have established gaming control boards to regulate the possession and use of slot machines.

Nevada is the only state that has no significant restrictions against slot machines both for public and private use. In New Jersey , slot machines are only allowed in hotel casinos operated in Atlantic City.

Several states Illinois , Indiana , Louisiana and Missouri allow slot machines as well as any casino-style gambling only on licensed riverboats or permanently anchored barges.

Since Hurricane Katrina , Mississippi has removed the requirement that casinos on the Gulf Coast operate on barges and now allows them on land along the shoreline.

Delaware allows slot machines at three horse tracks; they are regulated by the state lottery commission.

In Wisconsin, bars and taverns are allowed to have up to five machines. These machines usually allow a player to either take a payout, or gamble it on a double-or-nothing "side game".

A player redeems his winnings by pressing a button to print a ticket, which the bartender redeems for cash. The territory of Puerto Rico places significant restrictions on slot machine ownership, but the law is widely flouted and slot machines are common in bars and coffeeshops.

The remaining states allow slot machines of a certain age typically 25—30 years or slot machines manufactured before a specific date. For a detailed list of state-by-state regulations on private slot machine ownership, see U.

Native American casinos located in reservations are not permitted to have slot machines unless the tribe first reaches a pact with the state in which it is located per Indian Gaming Regulatory Act.

Typically, a pact entitles the state to receive a fraction of the gross revenue from slot machines. Some states have restrictions on the type called "class" of slot machines that can be used in a casino or other gaming area.

The Indian Gaming Regulatory Act establishes three classes of games with a different regulatory scheme for each: Class I gaming is defined as 1 traditional Indian gaming, which may be part of tribal ceremonies and celebrations, and 2 social gaming for minimal prizes.

Class II gaming is defined as the game of chance commonly known as bingo whether or not electronic, computer, or other technological aids are used in connection therewith and, if played in the same location as the bingo , pull tabs, punch board, tip jars, instant bingo, and other games similar to bingo.

Class II gaming also includes non-banked card games , that is, games that are played exclusively against other players rather than against the house or a player acting as a bank.

The Act specifically excludes slot machines or electronic facsimiles of any game of chance from the definition of class II games. Tribes retain their authority to conduct, license, and regulate class II gaming, provided it complies with the Act - including the requirement that the Tribal government adopt a gaming ordinance approved by the National Indian Gaming Commission NIGC.

Tribal governments are the primary entity responsible for regulating class II gaming on its lands. Only Hawaii and Utah continue to prohibit all types of gaming.

The definition of class III gaming is broad. It includes all forms of gaming that are neither class I nor II. Games commonly played at casinos , such as slot machines , blackjack , craps , and roulette , clearly fall in the class III category, as well as wagering games and electronic facsimiles of any game of chance.

Generally, class III is often referred to as casino-style gaming. The regulatory scheme for class III gaming is more complex than a casual reading of the statute might suggest.

Although Congress clearly intended regulatory issues to be addressed in Tribal-State compacts , it left a number of key functions in federal hands, including approval authority over compacts, management contracts, and Tribal gaming ordinances.

Congress also vested the Commission with broad authority to issue regulations in furtherance of the purposes of the Act.